C.M.
Hi B.,
We used to live in Plano and had our son (now 4 1/2) at Carpe Diem Private Preschool in Richardson from ages 1-3. ...And LOVED it!!!! It fits every criteria you listed - as mine are still similar. They have a location in Frisco as well where they offer Kindergarten. I am heartbroken that we had to leave - we moved down South to the M-streets about a year ago. Check out their website - www.carpediempreschool.com
Good luck -
C.